System for deviating part of the external paneling of a motor vehicle

ABSTRACT

The invention relates to a system for deviating part of an external panel of a motor vehicle, during an accident to reduce the impact energy of a person colliding with deviated part of the external panel. The part is displaced in a deviation direction that is opposite to that of an impact direction of the person. The system includes a device for deviating the part. The device is engaged at least at one point on the part and permits a displacement of the part in the impact direction, if a person collides with the part.

BACKGROUND

The invention relates to an arrangement for deflecting part of theexternal paneling of a motor vehicle in the event of a crash.

The deflection of part of the external paneling of the motor vehicletoward the outside in the event of a crash is intended to dissipate theimpact energy of a person (e.g., a pedestrian or cyclist) in acontrolled manner. The impact energy of the person is dissipated bymovement of the deflected part in a deflecting direction that is counterto an impact direction of the person, thereby reducing the likelihood ofthe person coming into contact with rigid motor vehicle elementspositioned behind the external paneling, such as, for example, an engineblock. To this end, a typical arrangement comprises a device fordeflecting the part of the external paneling, which device acts on atleast one point of this part and which, during the impact of a person,permits a movement of this part counter to the deflecting direction,thereby dissipating impact energy.

An arrangement of this type is disclosed, for example, in WO 01/23 225A1 (incorporated by reference herein), which describes a device forraising the engine hood of a motor vehicle in the event of crash, whichcan be detected by a pre-crash sensor. The sensor triggers a raising ofthe engine hood if it detects a directly imminent, unavoidable accident.A person impacting against the engine hood, as a consequence of thisaccident, is protected (by the raising of the engine hood) from cominginto contact with the engine block situated under the hood.

As the impact of a person against the engine hood (and the associatedimpact forces) leads to a movement of the engine hood counter to thedeflecting direction (i.e. the impact and associated forces lead to acounter deflection of the engine hood toward the engine block), energymay be dissipated in a controlled manner. As a result, the risk ofinjury is reduced in comparison with a direct impact against a rigidpart of the motor vehicle.

However, a problem with this arrangement is that the impact of a personagainst the external paneling of a motor vehicle (e.g., against theengine hood thereof) frequently takes place in a number of steps. Forexample, during the usual kinematic sequence of a collision between apedestrian and vehicle, the impact of the pedestrian's head against theengine hood is generally preceded by an impact of the pedestrian's upperbody. The impact of the upper body (and its associated impact energy)may result in the previously deflected engine hood being lowered backagainst the engine block. As a result, there may no longer sufficientprotective potential for the subsequent impact of the head. However, itis the protection of the head of a person (e.g., pedestrian or cyclist)colliding with the vehicle that is of particular importance.

SUMMARY

The embodiments of the invention described herein improve upon theconventional arrangement by accounting for multiple impact stages. As aresult, the invention accounts for and dissipates, for example, theimpact energy of a pedestrian's head after accounting for anddissipating, for example, the impact energy of the pedestrian's upperbody.

In accordance therewith, the deflecting device serving for deflectingpart of the external paneling of the motor vehicle can be controlled asa function of the location, the time and/or the direction of the impactin such a manner that, as a function of the instant of the impact (afterthe triggering of the deflecting device or after a preceding firstimpact) against the part of the external paneling and/or as a functionof the location of the impact against the deflected part of the externalpaneling and/or as a function of the direction of the impact against thedeflected part of the external paneling, the deflecting device permitsor does not permit a movement of the part of the external panelingcounter to the deflecting direction.

This makes it possible to control the deflecting device as a function ofexperimental values concerning the time sequence of the impact of theupper body of a person, on the one hand, and of his head, on the otherhand, and as a function of experimental values concerning the locationand the direction of the impact of the upper body, on the one hand, andof the head, on the other hand, in such a manner that it permits amovement counter to the deflecting direction specifically at the momentwhen, according to the available experimental values, the head of aperson situated outside the vehicle is striking against the deflectedpart of the external paneling of the vehicle, for example against adeflected engine hood.

On account of the mobility and deformability of the deflected part ofthe external paneling, the feature according to which the deflectingdevice permits or does not permit a movement of the part of the externalpaneling counter to the deflecting direction is not absolutely to beunderstood within the meaning of either a movement of the externalpaneling taking place or alternatively no movement thereof at all takingplace. On the contrary, depending on the severity of the impact, acertain movement is imposed on the system even in those cases in whichno movement per se of the external paneling counter to the deflectingdirection is to take place. Rather, the crucial factor for the featureis for the deflecting device to be controlled in such a manner that,under given conditions (as a function of the instant, the location andthe direction of the impact), opens up the possibility of a movement ofthe part of the external paneling counter to the deflecting direction oropposes this movement in order as far as possible to prevent it.

The solution according to the invention firstly provides, by part of theexternal paneling being deflected, a deformation distance in order todissipate the energy transmitted by the head of a pedestrian or acyclist to the external paneling to an acceptable level without his headcoming into contact with rigid vehicle parts situated behind theexternal paneling, such as, for example, the engine block. In this case,the effect achieved by controlling the deflecting device is that thisdeformation distance is not already used up during an impact of theupper body that precedes the impact of the head. On the contrary, theavailable deformation distance is not as far as possible to be reducedduring an impact of the upper body that precedes the impact of the head.

An accident which leads to the deflecting device being activated can bedetected by a contact sensor or a proximity sensor (pre-crash sensor).Upon detection of an accident, the corresponding sensor produces asignal causing the deflecting device to deflect the corresponding partof the motor vehicle outward. In this case, the activation of thedeflecting device and the impact of the head must not coincide in time.This causes correspondingly short deflecting times. To this end, thecorresponding part of the external paneling of the motor vehicle, forexample the engine hood, is to be designed in such a manner that it canbe brought into the deflected position (protective position) withoutpermanent deformation. On the other hand, the external paneling mustnot, however, be of such rigid design that the load limit values of thehead are exceeded solely because of the rigidity of the externalpaneling.

In particular, the external paneling has to be of sufficiently flexibledesign even in the region of the points on which the deflecting deviceacts, so that the load limit values for the head are not exceeded.

Overall, the arrangement according to the invention results in a uniformand low loading of the head during the impact against part of theexternal paneling of a motor vehicle, in order to avoid serious headinjuries.

To control the deflecting device as a function of the instant of theimpact, provision may be made for the deflecting device to permit amovement of the deflected part of the external paneling counter to thedeflecting direction only after a specified period of time has elapsedsince the activation of the deflecting device by the force with whichthe deflecting device acts on the deflected part of the externalpaneling being time-controlled. The control takes place here in such amanner that the force with which the deflecting device acts on theexternal paneling decreases with time after the deflection of the partof the external paneling. This means that, upon an impact of the upperbody of a person directly after part of the external paneling has beendeflected, the force applied by the deflecting device is stillsufficiently large in order to prevent a restoring movement of the partof the external paneling. During the subsequent impact of the head, theforce has decreased sufficiently now for it to be possible for energy tobe dissipated in a controlled manner by the part of the externalpaneling moving counter to the deflecting direction and thereforecounter to the direction of action of the pressure.

To this end, use may be made of a deflecting device which deflects thepart of the external paneling which is to be deflected under the actionof the pressure of a fluid, in particular of a gas, the pressure of thefluid being time-controlled and decreasing after the deflection of thepart of the external paneling, thus enabling the part of the externalpaneling to move counter to the pressure of the fluid.

The pressure of the fluid acting on the deflected part of the externalpaneling can be reduced, for example, by some of the fluid beingdischarged by corresponding outflow openings being provided fordischarging the fluid. In addition, the size of these outflow openingsmay be controllable in order to be able to set the pressure of the fluidin a specific manner as a function of the time.

The triggering of the deflecting device may take place, for example,pyrotechnically, it furthermore also being possible for the productionor release of a gas used for deflecting the external paneling to takeplace pyrotechnically.

According to one embodiment, the deflecting device comprises an elementwhich can be filled with fluid to produce the pressure, for example aninflatable airbag, which acts on the part of the external paneling thatis to be deflected. According to another embodiment, the deflectingdevice has a piston (e.g. guided in a cylinder) which acts on the partof the external paneling which is to be deflected and is moved, forexample, by means of a pressure produced by a fluid.

According to another variant of the time control of the deflectingdevice, the deflecting device can be locked in such a manner that, inthe locked state, it does not permit any movement of the deflected partof the external paneling counter to the deflecting device, the lockingbeing releasable by the impact of a body part (e.g. the upper body) of aperson against the external paneling, so that, upon a further impact(e.g. of the head), the deflected part of the external paneling can movecounter to the deflecting direction. The locking may take place, forexample, by means of a hook which is released owing to the forceproduced upon a first impact.

According to a further variant of the invention, the deflecting devicepermits a movement of the deflected part of the external panelingcounter to the deflecting direction Only upon the impact of a body partof a person within a certain region of this part. This region isselected in such a manner that it precisely encompasses those points ofthe part of the external paneling against which, according to theavailable experimental values, the head of a pedestrian or of a cyclistimpacts during a typical accident sequence.

In one preferred embodiment, that region encompasses in particular thosepoints of the external paneling on which the deflecting device acts. Tothis end, the deflecting device may act on the external paneling via anelastically or plastically deformable element. The corresponding elementmay also be of multipart design, with the result that the deformabilityis achieved by the movement of two components of the element withrespect to each other, for example by the movement of a piston in acylinder.

When a person impacts against the external paneling of the motor vehiclein the environment of the elastically or plastically deformable element,said element is deformed in such a manner that the deflected part of theexternal paneling can move counter to the deflecting direction (withdeformation of each element).

The deformable element can be formed, for example, by a spring-elasticelement, by a flexible coupling element of the deflecting device (e.g.in the form of a flexible traction means) or by a telescopic element(e.g. in the form of a piston guided in a cylinder).

As an alternative or in addition to a deformable element, provision maybe made for the deflecting device to be of reversible or at leastpartially reversible design, so that, upon the impact of a body part ofa person (within a certain region of the external paneling), thoseelements of the deflecting device which serve for deflecting theexternal paneling directly permit the part of the external paneling tomove counter to the deflecting device.

According to a further variant of the invention, the deflecting devicepermits a movement of the deflected part of the external panelingcounter to the deflecting direction only if the impact of a body part ofa person against the external paneling takes place along a certain,specifiable directional region (corresponding to a specified region ofpossible force application directions).

This may be achieved, for example, by the use of a deformation elementwhich can be deformed only upon an impact with a force applicationdirection within the specified solid angle region. According to anotherembodiment with a reversible or partially reversible deflecting device,the latter, on account of its reversibility, only permits a movement ofthe external paneling if the force exerted on the deflecting device hasa direction which lies within the specified directional region.

For deflecting part of the external paneling of the motor vehicle, thedeflecting device may have, for example, a lever mechanism with at leastone pivotable lever. On the other hand, the deflecting device maycomprise a movably guided traction means which is tightened for thedeflection of part of the external paneling.

In order to permit a movement of the deflected part of the externalpaneling counter to the deflecting direction, the pivotably mountedlever of the deflecting device is pivoted in the opposite direction andthe part of the external paneling that is to be moved is moved counterto the tensioning of the traction means. In this case, the pivotablelever and the traction means may be arranged and designed in such amanner that a movement of the deflected part of the external panelingcounter to the deflecting direction is possible only if the forceexerted by the impact of a body part (in particular the head) of aperson acts on the deflected part in a certain subregion and/or with acertain direction.

In a corresponding manner, provision may also be made, in the case ofpart of the external paneling being deflected by means of a piston, forthe piston to be arranged in such a manner and to be guided in such amanner that a movement of the deflected part counter to the deflectingdirection is possible only upon an impact against a certain region ofthe deflected part and/or upon a certain force application direction.

In a development of the invention, the deflecting device is coupled toan elastic element which pretensions the deflecting device in thedeflecting direction. Furthermore, a locking element is provided whichopposes a deflection of the corresponding part of the external panelingby the deflecting device and which, in the event of a crash, can beunlocked either under control by a sensor or by the force producedduring the impact of a person.

The solution according to the invention can be used particularlyadvantageously for deflecting (raising) a flap of a motor vehicle, forexample the engine hood or the trunk flap, in the event of a crash, inwhich case the application point of the deflection device is preferablyto be arranged in the region of that end of the corresponding flap whichis on the passenger compartment side.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory only,and are not restrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become apparent from the following description, appendedclaims, and the accompanying exemplary embodiments shown in thedrawings, which are briefly described below.

FIG. 1 a shows a schematic illustration of an arrangement for raising anengine hood by means of an inflatable airbag;

FIG. 1 b shows the arrangement from FIG. 1 a after the raising of theengine hood;

FIG. 2 a shows a schematic illustration of an arrangement for raising anengine hood by means of a piston which can be moved by gas pressure;

FIG. 2 b shows the arrangement from FIG. 2 a after the raising of theengine hood;

FIG. 3 a shows a modification of the exemplary embodiment from FIG. 2 a;

FIG. 3 b shows the arrangement from FIG. 3 a after the raising of theengine hood;

FIG. 4 a shows a schematic illustration of an arrangement for raising anengine hood using a traction means;

FIG. 4 b shows the arrangement from FIG. 4 a after the raising of theengine hood;

FIG. 5 a shows a development of the exemplary embodiment from FIG. 4 a;

FIG. 5 b shows the arrangement from FIG. 5 a after the raising of theengine hood;

FIG. 6 a shows a schematic illustration of an arrangement for raising anengine hood using a pivot lever and a spring acting thereon;

FIG. 6 b shows the arrangement from FIG. 6 a after the raising of theengine hood;

FIG. 7 shows a schematic illustration of an arrangement for raising anengine hood using a lever system;

FIG. 8 a shows a schematic illustration of an arrangement for raising anengine hood using a pivotably mounted piston;

FIG. 8 b shows the arrangement according to FIG. 8 a after the raisingof the engine hood;

FIG. 9 a shows a schematic illustration of an arrangement for raisingthe outer side of an engine hood by means of an inflatable airbag;

FIG. 9 b shows the arrangement from FIG. 9 a after the raising of theengine hood;

FIG. 10 shows a schematic illustration of an arrangement for raising anengine hood using an airbag which additionally covers regions of a motorvehicle that are adjacent to the engine hood;

FIG. 11 shows a schematic illustration of an arrangement for raising anengine hood using an airbag which extends along the outer edges of theengine hood;

FIG. 12 a shows a hinge for an engine hood for use in one of thearrangements according to FIGS. 1 a to 11;

FIG. 12 b shows the hinge according to FIG. 12 a after the raising of anengine hood.

DETAILED DESCRIPTION

FIG. 1 a schematically shows an engine hood M of a motor vehicle in theregion of its rear end H, i.e. in the region of its end facing thepassenger cell, in particular the windshield.

In the region of an end H of the engine hood M, which is at the rear inthe direction of travel and faces the passenger cell, a deflectingdevice 1 is arranged between a load-bearing structure T of the motorvehicle and the engine hood M. The deflecting device 1 can be used toraise the engine hood M in the event of a crash, to provide adeformation distance s (shown in FIG. 1 b) for a person, e.g. apedestrian or a cyclist, impacting against the engine hood M as aconsequence of the accident. The deflecting device 1 includes an airbag10, which is arranged on the load-bearing structure T of the motorvehicle. The airbag 10 can be inflated by means of a gas generator 12and, in the folded state (shown in FIG. 1 a), extends between theload-bearing structure T and the engine hood M. Arranged on the enginehood M above the airbag 10 is a force transmission element 15 via whichthe airbag 10 can act on the engine hood M.

If, by means of a “pre-crash sensor” in the form of a proximity sensor,a directly imminent, unavoidable accident is identified or if, by meansof a contact sensor, an accident which is already taking place isidentified, then the deflecting device 1 is triggered by the gasgenerator 12 being ignited. The gas generator 12 produces a gas by meansof a pyrotechnic charge and/or releases an already stored gas whichflows into the airbag 10, so that the latter is inflated and isdeployed.

When the airbag 10 is inflated, it presses (via the force transmissionelement 15) against at least part of the engine hood M, so that the partis raised in a deviation direction a, as illustrated in FIG. 1 b. In thecompletely inflated state of the airbag 10, the engine hood M is raisedin the region of its rear end H by a defined distance s in relation toits starting position illustrated in FIG. 1 a. This distance s definesthe deformation distance that is available to a person (e.g., apedestrian or cyclist) impacting against the engine hood M as aconsequence of an accident. As a result, the impact energy of the personimpacting the hood M in an impacting direction (which is counter to thedeviation direction) can be dissipated in a controlled manner. Moreover,the likelihood of the person coming directly into contact with rigidvehicle parts (which may be situated behind the engine hood M, such as,for example, the engine block) is reduced.

To this end, the engine hood M should be sufficiently stable, so that itcan be raised, without being damaged, by means of an airbag 10, whichcan be inflated very rapidly within milliseconds. In addition, theengine hood M should be sufficiently flexible, so that an impactingperson does not sustain severe injuries due to the rigidity of theengine hood M.

Immediately after the inflation of the airbag 10, the airbag 10 (as aresult of the gas pressure existing in the airbag 10) forms an elementthat keeps the engine hood M stable in the raised position. Upon impactof a person against the engine hood M, the airbag 10 initially yieldsonly to a small extent such that a substantial movement of the enginehood M counter to the deflecting direction a of the engine hood is notpossible. That is to say, a first impact of a body part (e.g., an upperbody) of the person involved in the accident against the engine hood Mimmediately after the upward deflection of the engine hood M byinflation of the airbag 10 does not result in the engine hood M beingmoved counter to the deflecting direction a. As a result, the energy ofthe initial impact is not substantially dissipated in a controlledmanner. However, the deformation distance s is still available for alater, second impact (as hereafter described) and, therefore, thedeformation distance is available to dissipated the energy of the secondimpact in a controlled manner.

During a later, second impact, a movement of the engine hood M counterto its deflecting direction a is made possible by the fact that theairbag 10 has vent openings as are known, for example, in the case ofairbag modules for protecting vehicle occupants, through which the gaswhich has flowed from the gas generator 12 into the airbag 10 can bedischarged again into the surroundings. By this means, the pressurewithin the airbag 10 decreases, so that during a later impact, e.g. ofthe head of a person, against the engine hood M, a considerably lowerpressure opposes a movement of the engine hood M counter to thedeflecting direction a. The engine hood M can then move counter to thedeflecting direction a under the action of the force of the impact, inwhich case impact energy is now dissipated in a controlled manner and aninjury to the head impacting against the engine hood M is prevented.

In this connection, it should be noted that even upon the first impactof the person with his upper body against the engine hood M, thedeflecting device nevertheless still fulfills a second main function,namely of protecting the person against coming directly into contactwith rigid vehicle parts placed below the engine hood M, such as, forexample, the engine block.

As a result, the arrangement illustrated in FIGS. 1 a and 1 b istherefore used to protect a person impacting against the engine hood Mduring a first impact directly after the inflation of the airbag 10against coming into contact with rigid vehicle parts placed below theengine hood M, by raising the engine hood M. Upon a later, second impactthere is furthermore (additionally) still a controlled dissipation ofimpact energy with the engine hood M moving counter to the deflectingdirection a.

Since, in the case of an accident-induced impact of a person against theengine hood of a motor vehicle, generally first the upper body and thenthe head impacts against the engine hood, the greatest possibleprotection is provided for the impacting head and, in particular, areduction in the deformation distance s even before the impact of thehead is prevented.

In a development of the arrangement illustrated in FIGS. 1 a and 1 b,the size of the vent openings serving for discharging gas from theairbag 10 can be time-controlled, so that a certain, specified timewindow can be made available in a specific manner, in which adissipation of impact energy is possible by the engine hood M movingcounter to the deflecting direction a. In this case, provision may alsobe made, for example, for the force acting during a first impact againstthe engine hood M and the deflecting device 1 to change the size of thevent openings in such a manner that a certain specifiable pressure levelis made available for the second impact of the person (with his head)that is to be anticipated within a certain period of time.

As modification of the exemplary embodiment illustrated in FIG. 1 a,FIG. 2 a illustrates an arrangement for raising the engine hood M, thedeflecting device 2 comprising, instead of an airbag, a piston 21 whichis guided in a cylinder 20, can be raised by a gas produced by means ofa gas generator 22 and then, according to FIG. 2 b, acts via a forcetransmission element 25 on the engine hood M in such a manner that thelatter is raised by a defined distance s along a deflection direction a.

In this case too, the pressure with which the deflecting device 2 actson the engine hood M in the region of its rear end H can be varied bygas being discharged from the piston/cylinder arrangement 20, 21. It isthereby possible, in the same manner as in the exemplary embodimentillustrated in FIGS. 1 a and 1 b, for a movement of the engine hood Mcounter to the deflecting direction a to initially still not be possibledirectly after the engine hood M has been deflected by means of thepiston 21 whereas, at a later instant, after gas has been dischargedfrom the deflecting device 2, the engine hood M can be moved counter tothe deflecting direction a, with the piston 21 again being displaced acertain amount into the cylinder 20.

FIG. 3 a illustrates a modification of the arrangement from FIG. 2 a,according to which the deflecting device 2, comprising a cylinder 20with piston 21 (compare FIG. 3 b), is connected to the engine hood M inthe region of its rear end H on the passenger-cell side via a forcetransmission element in the form of a deformation element 26. Thisdeformation element 26 can be of such elastically deformable design thatit yields when a person impacts against the engine hood M in theenvironment of the deformation element 26, and thus permits a movementof the engine hood M counter to the direction a along which it had beenraised previously, according to FIG. 3 b, by the piston 21 of thedeflecting device 2 being raised.

The deformation element 26 can be provided as an addition or alternativeto the time control of the deflecting device 2 that is described withreference to FIGS. 2 a and 2 b. That is to say, the deformation element26 permits the engine hood M to move counter to the deflecting device aeven if the piston 21 cannot be pushed back into the cylinder 20 upon animpact of a body part against the engine hood M. However, it isimportant for the impact in the environment of the deformation element26 to take place in the region of the rear end H of the engine hood M,i.e. in the region in which, during an accident, a person's headfrequently strikes and then acts with a corresponding force F_(h) on theengine hood M.

The design of the force transmission element (26) as a deformationelement is in particular of importance if the deflecting device (2) isnot of reversible design, i.e. the piston (21) cannot be pushed backagain into the associated cylinder 20 under the action of the force(F_(h)) occurring during the impact of the head.

By contrast, forces F_(b) which arise from an impact in the region ofthe front end V of the engine hood M and arise, for example, from theimpact of a person's legs do not result in a deformation of thedeformation element 26 and therefore in the engine hood M moving counterto its deflecting direction a. This is, inter alia, a consequence of thecurved design of the engine hood M.

With the exemplary embodiment illustrated in FIGS. 3 a and 3 b, aspatial control of the deflecting device 2 (if appropriate in additionto the time control described with reference to FIGS. 1 a to 2 b) cantherefore be achieved in such a manner that, after the engine hood M israised, a movement counter to the deflecting direction a and thereduction in the deformation distance made available during thedeflection only take place if the impact in the environment of thedeflecting device 2 takes place at the rear end H of the engine hood M.Since the head of a pedestrian or cyclist involved in the accidentfrequently impacts in this region, this serves in turn for a specialprotection of the head of the corresponding person.

Furthermore, provision may be made for the force/distance characteristicof the deformation element 26 to be anisotropic, for example by aparticularly severe deformation of the deformation element 26 beingpossible if the corresponding force F_(h) acts essentiallyperpendicularly to the engine hood M, as is frequently the case upon animpact of a head.

In the exemplary embodiment, shown in FIG. 4 a, of an arrangement forraising the engine hood M in the region of its rear end H facing thewindshield W, the deflecting device 3 comprises a traction means 31which engages at one end on a force transmission element 35 provided onthe engine hood M and is arranged at the other end in a tensioningdevice 32. The flexible traction means 31 can be formed, for example, bya cable and is deflected at least once between its two ends by means ofa deflecting element 30.

In the event of a crash the tensioning device 32 is activated and then,for example by means of a pyrotechnic charge or by means of an electricdrive, exerts a tensile force on the traction means 31, so that thelatter is tightened, with the engine hood M being raised, according toFIG. 4 b, in the region of its rear end H. When the engine hood M israised in the region of its rear end H, it pivots about a pivot, whichis formed at its front end V, in the hood lock. The distance by whichthe engine hood M is raised in the region of its rear end H compared toits starting position (illustrated by dashed lines in FIG. 4 b) dependshere on the position of the deflecting element 30. The force with whichthe engine hood M is held in its raised position depends in turn on thetensioning of the traction means 31 that is produced by the tractiondevice 32.

Upon an impact of a person's head against the engine hood M in theregion of its rear end H as a consequence of an accident, the enginehood M can be moved counter to the deflecting direction a because of theimpact force F_(h) effective here counter to the action of thetensioning of the traction means, thus enabling impact energy to bedissipated in a controlled manner. In this case, the extent of themovement depends on the location of the impact in the region of the rearend H of the engine hood M and on the direction of the associated forceF_(h).

By contrast, impact forces F_(b) which occur because of the impact of abody part, e.g. the legs, in the region of the front end V of the enginehood M, do not cause the engine hood M to move counter to the deflectingdirection a. In this case too, the curvature of the engine hood M isagain of importance.

If appropriate, the tensioning at which the traction means 31 is keptmay also be varied in time, for example may be reduced with increasingduration of time after the deflecting device 3 has been activated.

FIG. 5 a illustrates a development of the exemplary embodiment from FIG.4 a, in which, to raise the engine hood M, there is additionallyprovided a sloping plane 37 which is connected to the engine hood M viaa deformation element 36 and which interacts with a rotationallysymmetrical element 38 arranged in a positionally fixed manner on aload-bearing part of the motor vehicle. The design of the sloping plane37, e.g. the length and inclination thereof, defines the distance bywhich the engine hood M is raised by tightening of the traction means 31when the traction device 32 is activated, compare FIG. 5 b. Since thesloping plane 37 is connected to the engine hood M via a deformationelement 36, the possibility, described with reference to FIGS. 4 a and 4b, of the engine hood M moving counter to the deflecting direction aunder the action of appropriate impact forces is not obstructed.

In the arrangement, illustrated in FIG. 6 a, for raising the engine hoodM in the region of its rear end H in the event of a crash, thedeflecting device 4 has a lever 41 which is mounted pivotably about apivot 40 and is coupled at one end 41 b (compare FIG. 6 b) to a springelement 42. This spring element 42, which is designed as a tensionspring, is fixed at the other end on a load-bearing body part T andexerts on the pivot lever 41 a force which has the tendency to pivot thelatter about the pivot 40, in which case the engine hood M would beraised in the region of its rear end H. However, this pivoting movementis prevented by a hook 43 which acts on the pivot lever 41 and whichprevents the pivoting movement which can be produced by the springelement 42.

If, as a consequence of an accident, a person impacts with a body partagainst the engine hood M in the region of the front end V, the impactforces F_(b) arising in this case cause the hook 43 to be unlocked andto thereby release the pivot lever 41. The latter then pivots about itsaxis of rotation 40 under the action of the spring element 42 and, inthe process, acts with its end 41 a facing away from the spring element42 against a force transmission element 45 arranged on the engine hood Min the region of its rear end H on the passenger-cell side, so that theengine hood M is raised there.

Even in its end position, illustrated in FIG. 6 b, after the engine hoodM is raised, the pivot lever 41 is still inclined in such a manner thatit is pivoted by an impact force F_(h), which acts in the region of therear end H of the engine hood M and may arise, for example, by theimpact of a person's head, counter to the action of the spring element42 in such a manner that the engine hood M can be lowered counter to itsdeflecting direction a. In this case, the spring constant of the springelement 42 determines the impact force required for moving the enginehood M. By contrast, the inclination of the pivot lever 41 in thedeflected state of the deflecting device 4 defines the directions of theforce F_(h) which may trigger a pivoting-back of the lever 41. The lessthe pivot lever 41 is inclined with respect to the vertical, the smalleris the directional region within which the direction of the force F_(h)has to lie in order to trigger a pivoting-back of the lever 41.

All in all, the selectable parameters which are important in thisdeflecting device 4 comprise the spring constant of the spring element42, the lengths of the two lever arms of the pivot lever 41, the mass ofthe engine hood M and the period of time required for raising the enginehood M.

In the arrangement illustrated in FIGS. 6 a and 6 b, a first impact of abody part of a person against the engine hood M therefore firstlyreleases the deflecting device 4 which then causes the engine hood M tobe raised and thereby makes available a deformation distance for asubsequent, second impact, in particular of the head of thecorresponding person.

In the exemplary embodiment illustrated in FIG. 7, the deflecting device5 for raising the engine hood M in the event of a crash comprises alever arrangement 51, 52 with a pivot lever 51, which is mountedpivotably about a pivot 50, and a push rod 52, which is coupled to abumper S of the vehicle. The push rod 52 is connected in an articulatedmanner to the lower end 51 b of the pivot lever 51. The upper end 51 aof the pivot lever 51 is guided in a longitudinal guide 57 which isfixed in turn on the engine hood M via a deformation element 55. In thiscase, the deformation element 55 and the longitudinal guide 57 arearranged in the region of the rear end H of the engine hood M directlyin front of the windshield W of the motor vehicle. If, in the event of acrash, a force F_(b) triggered by the impact of a person acts on thebumper S, then the latter triggers a movement of the push rod 52rearward in the longitudinal direction of the vehicle (counter to theforward direction of travel) which, in turn, produces a pivotingmovement of the pivot lever 51 about the axis of rotation 50. Thisraises the engine hood M in the region of its rear end H, the upper end51 a of the pivot lever 51 sliding in the longitudinal guide 57. As aresult, a deformation distance is made available for a subsequent,second impact against the engine hood M of the person affected by theaccident, in particular for the impact of the person's head against theengine hood M. Depending on the location and direction of the impact inthe region of the rear end H of the engine hood M, the deformationelement 55 and, if appropriate, a pivoting-back of the pivot lever 51make it possible for the engine hood M to move counter to the deflectingdirection A.

In the arrangement, illustrated in FIG. 7, for raising the engine hood7, instead of a lever mechanism a traction means or a sloping plane mayalso be provided as the deflecting means, in which case the latter wouldhave to be coupled in each case to the bumper S. Furthermore, the bumperS can interact with the push rod 52 via a step-up ratio in order toincrease the displacement distance of the push rod 52.

FIG. 8 a illustrates an arrangement for raising the engine hood M, thedeflecting device 6 of which is formed, as in the exemplary embodimentillustrated in FIG. 3 a, by a piston 61 which is guided in a cylinder 60(compare FIG. 8 b) and can be deflected by a gas-producing device 62 inorder to raise the engine hood M in the region of its rear end H. Thecoupling of the piston 61 to the engine hood M also takes place here viaa force transmission element 65. In contrast to the exemplary embodimentaccording to FIG. 3 a, in the present case the cylinder 60 is mountedpivotably about a pivot D on a load-bearing motor vehicle part T.

After the deflecting device 6 has been activated by means of a suitablesensor, the piston 61 and therefore also the engine hood M according toFIG. 8 b are raised, the cylinder 60 simultaneously being pivotedslightly about the axis of rotation D. The compressive force F_(f)existing in the cylinder 60 keeps the engine hood M in its deflectedposition. Upon an impact of a body part, in particular the head, of aperson against the engine hood M in the region of its rear end, saidengine hood can be moved counter to its deflecting direction a for thecontrolled dissipation of the impact energy if the force F_(h)associated with the impact opposes the force Ff produced by the gas inthe cylinder 60.

If, by contrast, an impact force F_(b) acts in the region of the frontend V of the engine hood M, which force is caused by a body partimpacting there, then this does not result in the engine hood M movingcounter to the deflecting direction a, since the corresponding forceF_(b) does not have a component or a sufficiently large componentopposing the force Ff exerted by the piston 61.

Furthermore, provision may be made for the piston 61 (e.g. in the regionof its piston rod) to interact with clamping elements which oppose adisplacement of the piston 61 counter to the deflecting direction a, thearrangement being designed in such a manner that the clamping forces ina typical impact of the upper body of a person are significantly greaterthan in the impact of the head, specifically in such a manner that adisplacement of the piston 61 counter to the deflecting direction a ispossible only in the case of an impact of a head.

FIG. 9 a shows a modification of the exemplary embodiment from FIG. 1 a,in which the deflecting device 1, which has an inflatable airbag 10, isarranged between a support structure Mt and the external paneling (outerside Ma) of the engine hood. That is to say, in the present case theengine hood M is of two-part design with a comparatively stable supportstructure Mt and an outer side Ma determining the external design of theengine hood M. According to FIG. 9 a, the airbag 10 is arranged in thefolded state between these components of the engine hood M, the supportstructure Mt of the engine hood M having a corresponding depression Rfor accommodating the airbag 10 and a gas generator 12, which protrudesinto the airbag 10, for inflating the airbag. The airbag 10 and the gasgenerator 12 are jointly fastened to the support structure Mt of theengine hood M by means of suitable fastening elements 13 (e.g. in theform of screws or rivets).

If a directly imminent accident or an accident which has alreadyoccurred is detected by a sensor, the airbag 10 is inflated by means ofthe gas generator 12 and, as a result, as can be seen with reference toFIG. 9 b, the outer side Ma of the engine hood M is lifted off thesupport structure Mt. By this means, a deformation distance for apedestrian or cyclist impacting against the outer side Ma of the enginehood M is again made available. The airbag 10 can be controlled in thesame manner as described above with reference to FIGS. 1 a and 1 b. Thatis to say, by a specific discharge of gas out of the airbag 10 after theouter side Ma of the engine hood M has been raised, the pressure levelwithin the airbag 10 and therefore also the force with which the airbag10 acts on the outer side Ma of the engine hood M can be varied in time.This takes place in particular with regard to setting a pressure levelat the instant of a probable impact of the head of a person who isinvolved in the accident and is situated outside the motor vehicle, thepressure level permitting the outer side Ma of the engine hood M to movecounter to its deflecting direction.

Due to the comparatively low rigidity of the outer side Ma of the enginehood M compared with a complete engine hood comprising the supportstructure Mt and outer side Ma, the airbag 10 has to have acomparatively large volume in order to support the outer side Ma of theengine hood M over an extensive area. This also permits the airbag 10 tobe subdivided into a plurality of chambers, of which the chambers to beassigned to an impacting upper body are filled first and with acomparatively high internal pressure while the chambers assigned to animpacting head (situated in the region of the rear end of the enginehood M) are filled following this and with a comparatively low internalpressure. This may be ensured, for example, by means of overflowopenings through which gas flows out of the chambers assigned to theupper body into the chambers assigned to the head. As an alternative, aplurality of airbags which are filled in a manner offset in terms oftime and with different internal pressures may be provided for thedifferent impact regions.

In the exemplary embodiment illustrated in FIG. 10, an airbag 10 againserves as the deflecting device 1 for raising the outer side Ma of anengine hood M with respect to the support structure Mt thereof in orderto protect a person situated outside the motor vehicle in the event ofan accident. In this case, the airbag, in the inflated state, issupported at one end on the support structure Mt and acts at the sametime on the outer side Ma of the engine hood M in such a manner that thelatter is deflected.

The airbag 10 here is designed in such a manner that it protrudes with arear section 100 behind the rear end H of the engine hood M andprotrudes with a further section 101 laterally next to the engine hoodM. A corresponding, laterally protruding section of the airbag 10 mayalso be provided on the other, opposite side of the engine hood M. Thesesections 100, 101 of the airbag 10 that protrude next to the engine hoodcan be used to cover additional regions of the vehicle body, such as,for example, fenders, the A-pillars and the frame of a window. Thisfurther reduces the risk of injury for a person situated outside themotor vehicle.

At the same time, this design of the airbag 10, which supports the outerside Ma of the engine hood M in the inflated state both in the region ofits rear end H and in the region of its longitudinal sides S, provides aparticularly homogeneous impact surface for an impacting person, so thata comparatively soft interception of the head, the upper body or otherbody parts of an impacting person is possible uniformly over the entireengine hood M.

The arrangement according to FIG. 10 can also be used in the same mannerfor the situation in which not only is the outer side Ma of the enginehood M, but also the entire engine hood M raised by a deflecting device1 in the form of an airbag 10.

In the exemplary embodiment according to FIG. 11, the engine hood M israised in its entirety, in the event of an accident, by a deflectingdevice 1 in the form of an essentially U-shaped airbag 10′ which extendswith its base section 100′ along the rear end H of the engine hood M andwith its two limbs 101′, 102′, which are angled away from the baseregion 100′, below the engine hood M along the longitudinal sides Sthereof. The engine hood M is therefore supported in the raised state onthree sides by means of the airbag 10′.

In the case of this arrangement too, homogeneous conditions are madeavailable over the entire surface of the engine hood M in the raisedstate of the engine hood M in order to intercept a person impactingagainst the engine hood M, irrespective of the location of the impactagainst the engine hood M, as softly as possible by the engine hood Mbeing moved counter to its deflecting direction.

In the exemplary embodiments, illustrated with reference to FIGS. 1 a to11, of an arrangement for raising an engine hood in order to protect aperson situated outside the motor vehicle, the engine hood M is pivotedin each case about its front end V (e.g. about a front lock subassembly)and, in the process, is raised in particular in the region of its rearend H. On the other hand, it is necessary, in order to swing up theengine hood in the event of a repair, to change the oil or for otherreasons, to be able to pivot the engine hood H about its rear end too.That is to say, the engine hood M has to be coupled in each case, on theone hand, in the region of its rear end H pivotably to the vehicle bodyin order to be able to swing said engine hood up for repair purposes,and, on the other hand, it has to be able to be raised in the region ofits rear end H in order to enable the protective function according tothe invention in an accident involving a person situated outside themotor vehicle.

A hinge with which these stipulations can be fulfilled is illustrated inFIG. 12 a. The hinge 9 has a base part 90 which is fixed on the vehiclebody, and an upper part 95 which can be pivoted with respect to the basepart 90 and can be connected to an engine hood. The upper part 95 isconnected to the base part 90 via two adjusting levers 91, 92 which areconnected in an articulated manner in the region of their lower ends, ineach case via hinge points 91 a, 92 a, to a retaining element 900, whichis connected to the base part 90, and in the region of their upper ends,in each case via further hinge points 91 b, 92 b, to the upper part 95of the hood hinge 9. This enables the upper part 9 to be pivoted withrespect to the base part 90 by means of the adjusting levers 91, 92, theengine hood being pivoted about its rear end, so that the front end ofthe engine hood swings upward and that region of the vehicle which isconcealed by the engine hood becomes accessible.

The retaining element 900, to which the two adjusting levers 91, 92 arepivotably coupled by their lower ends, is connected to the base part 90by means of two fastening elements 90 a, 90 b, e.g. in the form ofrivets. The fastening elements 90 a, 90 b of the elongated retainingelement 900 are provided here on the two ends of the retaining elementon the longitudinal side. The front fastening element 90 b in thedirection of travel—in the case of the hood hinge 9 being arranged in amotor vehicle in the region of the rear end of an engine hood—isdesigned in such a manner or has such a region of weakening that thefront connection between the base part 9 and the retaining element 900can be released in order to raise the rear end of the engine hood. Thisis because, after the front fastening element 90 b is released, the rearfastening element 90 a acts as a joint, with the result that theretaining element 900 can be pivoted about this rear joint 90 a withrespect to the base part 9. This is illustrated in FIG. 12 b. Theretaining element 900 then forms with the two adjusting levers 91, 92 alever arrangement which permits an essentially vertical raising of therear end of the corresponding engine hood, as is required in the case ofthe arrangements illustrated in FIGS. 1 a to 11.

The design, illustrated in FIGS. 12 a and 12 b, of a hood joint or hoodhinge 9 is therefore based on the principle of the hood hinge beingmodified by the action of certain specifiable forces in such a mannerthat a raising of the rear end of an engine hood (which is coupled tothe vehicle body via the hood hinge) is made possible. According to onealternative, the forces required for this can be applied by thedeflecting device 1 (cf. FIGS. 1 a to 11) itself, used for deflectingthe engine hood M. According to another embodiment, a separate devicemay be provided acting specifically on a certain section of the hoodhinge 9 in order to modify the latter in such a manner that the raisingof the rear hood end of the engine hood is made possible.

Of course, it is also conceivable to completely decouple the engine hoodin the region of its rear end from the vehicle body by destruction ofthe hood hinge 9. To this end, the adjusting levers 91, 92, for example,could be uncoupled either from the base part 90 or from the upper part95. The embodiment, illustrated in FIGS. 12 a and 12 b, of a hood hingewhich, for raising the rear end of an engine hood, is merely modified,but not destroyed, has the advantage of enabling the hood hinge 9 to beused at the same time to limit the raising of the engine hood M by meansof the deflecting device (in the manner of an intercepting strap), sothat excessive raising is avoided. This is because this could in turnresult in an impacting person striking against the rear edge of theengine hood, which could increase the risk of injury.

Given the disclosure of the present invention, one versed in the artwould appreciate that there may be other embodiments and modificationswithin the scope and spirit of the invention. Accordingly, allmodifications attainable by one versed in the art from the presentdisclosure within the scope and spirit of the present invention are tobe included as further embodiments of the present invention. The scopeof the present invention is to be defined as set forth in the followingclaims.

1. An automotive safety apparatus for protecting a person locatedoutside an automobile from an impact with a part of external paneling ofthe automobile comprising: a device configured to deflect the part ofthe external paneling of the automobile in a first deflecting directionfrom a first position to a second position, wherein after the device hasdeflected the part of the external paneling to the second position, thedevice is configured to oppose and control movement of the part of theexternal paneling in a second direction counter to the first deflectingdirection, the device including an element which, upon an impact of aperson against the deflected part in which impact forces act counter tothe first deflecting direction, can oppose a movement of the deflectedpart of the external paneling counter to the first deflecting directionin order to prevent the movement of the deflected part into the seconddirection, and wherein the device is configured to control movement ofthe part of the external paneling in the second direction counter to thefirst deflecting direction based upon the time of impact with the personin such a manner that, as a function of an instant of the impact againstthe part of the external paneling deflected to the second position, thedevice permits a movement of the part of the external paneling counterto the first deflecting direction or opposes such a movement in order toprevent the movement of the part counter to the first deflectingdirection.
 2. The apparatus of claim 1, wherein the device is configuredto use gas pressure to deflect the part.
 3. The apparatus of claim 2,wherein the device is configured so that the pressure of the gas iscontrolled over time to decrease after deflection of the part of theexternal paneling in the first deflecting direction.
 4. The apparatus ofclaim 3, wherein the device is configured so that the pressure of thefluid acting on the deflected part of the external paneling is reducedby discharging some of the gas.
 5. The apparatus of claim 4, wherein thedevice includes vent openings for discharging gas.
 6. The apparatus ofclaim 5, wherein the device is configured so that the size of the ventopenings can be controlled.
 7. The apparatus of one claim 2, wherein thegas pressure is produced pyrotechnically.
 8. The apparatus of claim 1,wherein the device can be triggered pyrotechnically.
 9. The apparatus ofclaim 1, wherein the device comprises an element which can be filledwith fluid so that when the element is filled the element applies aforce to the part of the external paneling.
 10. The apparatus of claim1, wherein the device comprises a piston which can apply a force on thepart of the external paneling.
 11. The apparatus of claim 10, whereinthe piston is configured to receive a fluid for extending the piston.12. The apparatus of claim 10, wherein a movement of the piston in thesecond counter to the deflecting direction can be triggered only upon animpact against the part of the external paneling within a specifieddirectional region.
 13. The apparatus of claim 1, wherein the device islockable in order to prevent any movement of the part counter to thedeflecting direction; and wherein the locking of the device can bereleased in response to the impact of the person against the part sothat the part is permitted to move counter to the deflecting direction.14. The apparatus of claim 13, further comprising a hook for locking thedevice.
 15. The apparatus of claim 1, wherein the apparatus isconfigured so that the deflecting device can be moved counter to thefirst deflecting direction only upon the impact of a body part of theperson within a certain region of the part of the external paneling. 16.The apparatus of claim 15, wherein the region surrounds a location onthe part against which the device applies a deflecting force.
 17. Theapparatus of claim 1, wherein the device includes an elastically orplastically deformable element.
 18. The apparatus of claim 17, whereinthe device is configured so that when a person impacts against the partof the external paneling, the elastically or plastically deformableelement deforms to permit the part of the external paneling to move inthe second direction counter to the first deflecting direction.
 19. Theapparatus of claim 18, wherein the deformable element comprises aspring-elastic element.
 20. The apparatus of claim 18, wherein thedeformable element comprises a flexible coupling element located betweenthe deflecting device and the part.
 21. The apparatus of claim 18,wherein the deformable element comprises a telescopic element.
 22. Theapparatus of claim 17, wherein the deformable element can be deformedonly after an impact force is applied from a predetermined directionwithin a predetermined region of the part of the external paneling. 23.The apparatus of claim 1, wherein the device is reversible, so that amovement of the part of the external paneling counter to the deflectingdirection is made possible by a movement of elements of the deflectingdevice in a direction counter to the first deflecting direction.
 24. Theapparatus of claim 1, wherein the deflecting device can be moved counterto the deflecting direction only upon the impact of a body part of aperson against a predetermined region of the part of the externalpaneling.
 25. The apparatus of claim 1, wherein device includes at leastone element configured so that the device permits a movement of the partof the external paneling in the second direction counter to the firstdeflecting direction only upon an impact within a specified directionalregion of the part of the external paneling.
 26. The apparatus of claim1, wherein the device includes a lever mechanism for deflecting the partof the external paneling.
 27. The apparatus of claim 1, wherein thedevice includes a movably guided traction mechanism for deflecting thepart.
 28. The apparatus of claim 26, wherein the lever mechanismincludes at least one lever which can be pivoted to deflect the part.29. The apparatus of claim 27, wherein the traction mechanism isconfigured to be tensioned to deflect the part.
 30. The apparatus ofclaim 29, wherein the device is configured so that in order to move thepart counter to the deflecting direction a load is applied to thetraction mechanism counter to its tensioning.
 31. The apparatus ofclaims 29, wherein the movement of the part counter to the tensioning ofthe traction mechanism is possible only upon an impact against the partwithin a specified directional region.
 32. The apparatus of claim 1,wherein the device is coupled to an elastic element which pretensionsthe deflecting device in the deflecting direction.
 33. The apparatus ofclaim 32, further comprising a locking element which prevents adeflection of the part by the device.
 34. The apparatus of claim 33,wherein the locking element is configured to be released by the impactof a person against the part.
 35. The apparatus of claim 1, wherein thedevice is configured to be activated by a first impact of the personagainst the vehicle, so that the part of the external paneling isdeflected in the first deflecting direction.
 36. The apparatus of claim35, wherein the device is configured to be activated when the forceproduced during the impact acts on the device.
 37. The apparatus ofclaim 1, wherein the device is configured to be activated based on asignal of a sensor coupled to the device.
 38. The apparatus of claim 1,wherein the part of the external paneling is formed by a flap of theautomobile.
 39. The apparatus of claim 38, wherein the flap is an enginehood or a trunk flap with two ends, wherein one end of the flap faces apassenger compartment of the automobile, and wherein the other end ofthe flap faces a direction counter to the passenger compartment.
 40. Theapparatus of claim 39, wherein the device is applied at the end of theflap facing the passenger compartment of the automobile.
 41. Anautomotive safety apparatus for protecting a person located outside anautomobile from an impact with a part of external paneling of theautomobile comprising: a device configured to deflect the part of theexternal paneling of the automobile in a first deflecting direction froma first position to a second position, wherein after the device hasdeflected the part of the external paneling, the device is configured tooppose and control movement of the part of the external paneling in asecond direction counter to the first deflecting direction, wherein thedevice is configured to control movement of the part of the externalpaneling in the second direction counter to the first deflectingdirection based upon either the time of impact with the person, thelocation of impact with the person, or the direction of impact with theperson, and wherein the device permits a movement of the part of theexternal paneling in the second direction counter to the firstdeflecting direction only a predetermined time period after the initialdeflection of the part of the external paneling in the first deflectingdirection.